By the mid-23rd century, the Medeusans had developed interstellar navigation to a fine art. During this time, Hikaru Sulu was considered a specialist in space navigation and weapons. (TOS: "Is There in Truth No Beauty?", "The Way to Eden")
Also during more ancient times on Earth, mariners navigated by the stars. Later, maps and globes were used, and with the advent of more advanced technologies such as the compass, sextant – and much later, RADAR and SONAR, Earth navigators gained access to more precise tools. (VOY: "Year of Hell"; ENT: "Borderland"; DS9: "Explorers")
Once beings began to travel the stars, the navigator, or "astrogation plotter", continued the role in space, while new technologies were developed to aid the role.
An early form of space navigation technology, referred to by Chakotay as "the old-fashioned way", were optical scanners. (VOY: "Unity") LIDAR, which used lasers, was another form of air and extra-atmospheric detection and ranging – especially for navigation – technology. (VOY: "One Small Step")
Subspace sensors later became a key external component in assisting starship navigation. (VOY: "Year of Hell", "The Fight") When the USS Enterprise was taken beyond the galactic barrier, they were unable to return because of the lack of reference points on which to plot a return course; this arose from the extreme sensory distortion, caused by the initial crossing of the barrier. (TOS: "Is There in Truth No Beauty?") Photic sonar was also used during this period. (Star Trek: The Motion Picture)
On occasion, when navigational sensors became inaccurate, inoperative or obsolete, alternative means could be used to assist in navigation.
In 2268, the Federation considered the possibility of employing Medeusan navigators aboard starships as a means of solving many navigational problems. (TOS: "Is There in Truth No Beauty?") Prior to this, the ship's computer banks were utilized to "solve our problems of navigation." (TOS: "The Way to Eden") During a ruse performed by Captain James T. Kirk in 2268, where the USS Enterprise crossed into the Romulan Neutral Zone, Kirk explained to the Romulan Commander that the inadvertent excursion across the zone was due to an "instrument failure caused navigational error." When the Romulan Commander questioned how an instrument failure as radical as Kirk suggested went unnoticed until you were well past the neutral zone, Kirk explained that "Accidents happen. Backup systems malfunction. We were due for overhaul two months ago." When again questioned by the Romulan Commander regarding the Enterprise's ability to navigate with said malfunction, Kirk explained that "the error was corrected." (TOS: "The Enterprise Incident")
During the Cardassian Occupation of Bajor, Kira Nerys learned "a little trick" that was used to evade the Cardassian ships while hiding in the Badlands. In effort to compensate for the limited sensor range in the Badland, the Bajoran pilots used an active scan system to navigate, a system which worked by echo location. According to Kira, this was accomplished by sending out "a modulated tetryon pulse and if it reflects off the hull of a ship we can approximate its location." To prevent the pulses from giving away the ship's position, they would alter course and speed following every scan. (DS9: "Starship Down")
In 2374, Seven of Nine and Harry Kim merged Starfleet and Borg ingenuity to create this new technology that incorporated "returning to that tried-and-true method" of navigating by the stars. The technology worked by using the astrometric sensors to measure the radiative flux of up to three billion stars at one time. The ship's computer would then calculate the ship's position relative to the center of the galaxy. The new mapping technology was considered to be ten times more accurate than current technology, and was able to eliminate five years from the ship's journey to Earth through the Delta Quadrant. (VOY: "Year of Hell")
The following year, when the USS Voyager became trapped in chaotic space, it was suggested that the ship "drop a series of beacons" to assist in their navigation out of that region of space. (VOY: "The Fight")